The overall goal of this research continues to be the further clarification of the role of iodine metabolism in the development of breast dysplasia and carcinoma. Published work from this grant shows that human breast tissue (1) takes up a definite quantity of radioactive iodine and (2) the amount present relates to the normalcy of the breast. The results from this and other reports from our laboratory suggest investigation to determine whether iodine uptakes can be used as a method for the early diagnosis of breast cancer. Presumably this would show abnormal tissue change much before clinical examination or mammography. The project is concerned with (1) improving methods of technic to simplify the approach, (2) comparison of the results with presently employed methodology on a long term basis, and (3) classification of the population employed historically and by existing symptomatology. In addition, the research has begun an evaluation of radioactive iodine imaging and a comparison analysis of thyroid uptake.